Should I make the swap to G3?

Just going off memory and quick math, the parts you mention are under $2K. That's with the Holley headers and not the $1K TTI headers!

FYI, I think the Holley kit moves the motor forward (and maybe down?). I was interested in their cross member reinforcement kit and trans mount for the TKX and I think I read it there? Not really sure but I think it was related to the SRV on the 6.4 motors and the coolant manifold for the 6.2 crashing with the firewall which Holley solved by pushing the motor forward. Seems like it was several inches, too. Only reason I bring it up is that unless you use their mounts with their headers, might be that the headers don't fit worth a darn. Just a heads up.

Keep me in mind if you build a completely new harness. Might be interested in your existing LA one. :D